#include <iostream>

using namespace std;

//struct 和 class区别
//struct 默认权限是 public
//class  默认权限是 private

class C1
{
    int m_a;
};

struct C2
{
    int m_a;
};

int main(void)
{
    C1 c1;
    C2 c2;

    //c1.m_a = 100;
    c2.m_a = 100;

    return 0;
}
